The western militia of that state had made some successful incursions into the country north-west of the Ohio, and had taken some British posts on the Mississippi.

These were erected in the county of Illinois; and a regiment of infantry, with a troop of cavalry, were raised for its protection.

The command of these troops was given to Colonel George Rogers Clarke, a gentleman whose courage, hardihood, and capacity for Indian warfare, had given repeated success to his enterprises against the savages.
This corps was divided into several detachments, the strongest of which remained with Colonel Clarke at Kaskaskia.

Colonel Hamilton, the Governor of Detroit, was at Vincennes with about six hundred men, principally Indians, preparing an expedition, first against Kaskaskia, and then up the Ohio to Pittsburg; after which he purposed to desolate the frontiers of Virginia.

Clarke anticipated and defeated his design by one of those bold and decisive measures, which, whether formed on a great or a small scale, mark the military and enterprising genius of the man who plans and executes them.
[Sidenote: 1779 February.] [Sidenote: Colonel Clarke surprises St.Vincents, and takes possession of it.] He was too far removed from the inhabited country to hope for support, and was too weak to maintain Kaskaskia and the Illinois against the combined force of regulars and Indians by which he was to be attacked so soon as the season for action should arrive.